1. Field of the Invention
The present invention relates to a cultivating apparatus which is applied to a carbon dioxide gas (CO.sub.2) incubator, a multi-gas incubator or the like to cultivate cultures such as cells, microorganisms, etc. while keeping the inside of the apparatus under an aseptic (germ-free) condition.
2. Description of the Related Art
A periodic sterilizing treatment is needed for a cultivating apparatus because cultures must be cultivated while keeping the temperature of the inside of the cultivating apparatus (chamber) and the concentration of carbon dioxide (CO.sub.2) to constant values and also keeping the inside of the chamber under an aseptic (germ-free) condition.
Further, in the cultivating apparatus as described above, when a cultivating container in which cultures are stocked is fed into or out of the chamber, the outside air invades into the chamber to thereby causing intrusion of the outside air containing various germs such as bacteria, etc. into the chamber. Since the cultivating apparatus is kept under such an environment that not only cultures, but also various germs are liable to grow, these germs may grow and contaminate the cultures.
There is known a conventional cultivating apparatus in which a germs-removing filter such as HEPA (High Efficiency Particulate Air) filter or the like is disposed to remove germs from gas circulating in the chamber.
Such a conventional cultivating apparatus containing a germs-removing filter has such a risk that once a secondary side of the germs-removing filter is contaminated with germs captured by the filter, the germs-removing/germs sterilizing effects of the filter are remarkably degraded because the germs captured by the germs-removing filter do not die, so that the cultures are contaminated by the germs.
Further, since the pore size of the germs-removing filter is smaller than the size of the germs, a pressure loss at the time when gas passes through the germs-removing filter is large and the germs-removing filter is liable to be clogged with the contaminants.